System of control.



H. T. MORRIS.

SYSTEM OF CONTROL.

APPLICATION FILED DEC.29.19I5.

1,302,068. Patented Apr. 29,1919.

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BY WM ATTORNEY -HURD "1. MORRIS, OF WILK INSBUBG,

PENNSYLVANIA, ASSIGNOR 'IO WESTINGHOUSE ELEGTBIC AND MANUFACTURINGCOMPANY, A COBPORATION OF PENNSYLVANIA.

SYSTEM} or common,

Specification of Letters Patent. Patented Apr. 29, 1919.

Application filed December 29,1915. Serial No. 69,182.

To all 10 ham it may concern Be it known that 1, Horn T. MORRIS, acitizen of the United States, and a resident of Vilkinsburg, in thecounty of Allegheny and State of Pennsylvania, have invented a new anduseful Improvement in Systems of Control, of which the cation. I,

My invention relates to control systems for electric vehicles andparticularly to control systems provided with alternating-currentcommutating motors of the doubly-fed ty e. I

Dne object of my invention is to provide a control system of the aboveindicated character provided with motors, having exciting and inducingfield-magnet windings, that shall be started as repulsion motors andshall be operated as doubly-fed motors.

7 Another object of my invention is to provide a control system, formotors of the above indicated character, with means whereby the voltagesupplied to the inducing field windings shall be varied in accordancewith the current supplied thereto.

A further object of my invention is to provide a control system, of theabove indicated character, with automatic means for varying the voltageimpressed on the inducing field windings that shall becontrolled by theamount of the current flowingthrough the inducing field windings.

More specifically, tion is to provide a control system with means thatshall reduce the voltagesupplied to the inducing field windings in casethe value of the current falls below a predetermined low limit, and withmeans that shall again raise the voltage sunpliedto the inducingwindings in case the value of the current supplied thereto is raisedabove a predetermined amount. 7

It has been found necessary to reduce the voltage of the'currentsupplied to the inducing field windings of a doubly-fed motor wheneverthe current supplied to the same falls below a predetermined value. Theabove object may be accomplished by shifting to a lower tap on thmaintransformer or by establishing a shunt circuit around the inducinging to my invention, the above object is accomplished a portion of themain transformer winding.

following is a specifi the ob] ect of my invenfield windings. However,accord- I bymeans of a separate auto-.. transformerwhich may beconnected. across In the accompanying drawings illustrat- 111g myinvention, Figure 1 is a diagrammatic view of themain power circuits ofa control system constructed in accordance with my invention; F'g. 2 isa diagrammatic view of the auxiliarycontrol circuits, Fig. 3 is a chartshowing the sequence in which the switches areoperated, and Fig. l is adiagrammatic view of the circuit relations for a particular position ofthe controller.

Referring to the drawings, an alternating current motor 1 of thecommutator type is provided with an armature2 and with an exciting fieldwinding 3 and an inducing field windingfl The motor 1 is supplied withpower from a trolley conductor 5 through a trolley 6 and a maintransformer 7 and is controlled bya set of switches 8, 9

and 10 and by a second set of switches 11 and 12. A switch 13 isprovided for establishing a short circuit around, the armature 2 whenthe motor is operated as a repulsion motor. 1 Preventive coils 1 k and15- are provided for preventing the short circuiting of any portion ofthe main transformer 7 when shifting from one transformer tap toanother. K

In the first set of switches, the switch '8 is adapted to bridge contactterminals 16 and 17 to connect transformer tap 18 to the preventivecoil14:. The switch 9 is adapted to bridge contact terminals 19 and 20 toconnect transformertapQl to the preventive coil 14. The switch 10isadapted to bridge contact terminals 22 and 23 to connect a transformertap 24to the preventive coil 14. In the second set of switches, the.switch 11 is adapted tobridge co tact terminals 25 and 26fto connecttransformer tap 27 to the preventive coil 15, the switch 12 is adaptedto bridge contact terminals 28 and 29 to connect a transformer tap 30 tothe preventive coil 15. The switch 11 is provided with an interlockwhich is adapted to bridge contact terminals 32 and 33, and the switch12 is provided with an interlock which is adapted to bridge contactterminals 3-5 and 36. The switch 13 is adapted to Current relays 52 and55 and an auxiliary that obtains when raise the 1elay'52 will, under the1 and 2, the motor 1 may be started and may be operated as 7 controllersuccessivelytO-POSltlOl'lS 0, cl, 6 and f. IIL'IIlOVIHg the a tactsegment 58 relay 67controlthe operation of the switches 40 and 41. Fig.2 illustrates the conditions flowing in which case the-low-current relay55 is raisedand the switch 40 is closed by being energized through theinterlock 69 of relay 67 and the interlock 4lout. The actuation of thehigh-current relay has no effect upon the circuit relations thusestablished but a sufiicient decrease in the current value to permit thelow-current relay 55 to close energizes the operating coil of the relay67 and causes the switch 40 to open. and the switch 41 to close bycompleting a. circuit for the coil of switch 41 from the battery throughinterlocks 70 and 4.0out., With the relay 67 in its uppermost position,a holding circuit for through interlock 68. An increase of the motorcurrentto a value sufficiently large to prevailing conditions;deenergizethe relay 67 and thereby reestablish the circuit conditions for normalmotor current.

The coils of the switches 8 to 13,, incllb slve, are energized bycurrent supplied from a battery B and are controlled by a mastercontroller lvC which embodiesa contact segment 58 and a plurality ofcontactfingers 59 to 66, inclusive, that are adapted to engagethesegment 58 for certaiiroi the controller positions at, 6,. c, (if ande. t With the systminPosition shown in Figs.

as a repulfsion motor by successiuely moving the master controller MCto" positions a and b a doubly-fed motor by moving the master mastercontroller MC, to position a, the con- 59 and 6.0,,"whereby a circuit isestablished 7 whichmaybe traced fromone terminal of,

aiidh? to close a the battery B through contact finger 59, controllersegment .58, [j i Contact terminal 73, interlock 6.9, terminal'74, coilof auxiliaryswitch 40, contact terminals 49 and 50 and, interlock'41-..- out to the other terminal of the battery B, auxiliary switch 4.0is,

Thus, ,the'coil of the energized, and the switch bridges contactterminals 42 and 43 to of the auxiliary windings 4to the preventive coil14. hen the master controller is and establishes a circuit which "may bemoved to position b, the controller segment traced from one terminal. ofthe battery B to contact finger 59, controller segment 58 and contactfingers'6Q, 61 and 62 and the energizing coils for switches 13 and 10,-in parallel, to the othertermrnal of the battery The switch 13-engagescontact terminals normal motor current is,

the same s completed movable,-

bridges the Contact fingers connect one terminal circuit around thearmature 2.' The switch 10 engages contact terminals 22 and 23 andestablishes a circuit which may be traced from the transformer: tap: 24,through. contact terminals 22 and 2?), switch 10, preventive coil 14,contact terminals 42 and 43, switch 40, coils of thelimit switches 52and 55, inducing and exciting field windings 4 and 3, contact terminal38, switch 13 and contact terminal 371to the transformer 7. Thus, themotor 1 is operated as a repulsion motor.

The; motor 1 is .Perated asa doubly-fed motor when the master controllerMO is in positions 0, cl; 2, 0r 1",. and, explaining the operation ofthe systemior the above controller positions,v it. will he assumed thatremains energized The closing of 12' establishes two circuits, onethrough the inducing field. J and another through-the exciting fieldwindings 3 and the. armature 2. The circuit through the inducing fieldvwinding may-be traced. from the tap of the main transformer 7 throughthe contact terminals 22 and. 2.3,.

switch, 10, preventive coil? 14, contact term-- male 42 and 43, switch4o, high and low-current, relays52 and 55,; inducing windings 4,preventive coil 15,. contact terminal 28, switch 12 and contaqtterminal2,9 to the tapv 30 of the main, transformer '7. The circuit througharmature 2 may be traced from the. preventive-coil 15, main: fieldwindings 3 and the armature 2 to the main transformer 72 the main fieldwindings and thewinding 4 In moving themaster controller successiwely topositions d; e and flswitches8, and 11 are."

operated, to: impress various voltages upon. the inducing, fieldwindings 4., exciting fieldwindings 13 and the armature. r a

Fig 4' represents the? simplified connections for position e,

In case. the current flowing through the circuit ofthe inducing fieldwindingst falls.

relays 52.1-

5.5 'ridge contact teiiniinalsv 57," respectively.-

53 and .54, and 5.6 and Thus, a circuit is established which may be.traced; from one termi a1; of the battery 3 through contact. finger 529,controller. seg% ment 58, interlock; 11 111. or l2- in,' accord-I .orswitch ,12 is in 68, coil or the. auxiliary relay gaged from contactterminal 71 and engages contact terminal 73. Accordingly, the. coil ofthe switch 40 is-deenergized and thecoil of the switch 41 is energizedIn this operation, the interlocks 40-out,.4l-out, 69 and 70 preventcontact terminals 47 and-48 willconnect theauto-transformer 39 acrossthe circuit of the inducing windings 4, and the opening of the switch 40will allow a tap 39 0f the autotransformer 39 to supply anypredetermined voltage. to the inducing windings 4 In case thecurrent-flowing through'the circuit of the inducing windings 4 is raisedto a value that will auxiliary relay 67 -will be broken and the initialcircuits will be reestablished; The circuit through the coil of.theauxiliary relay 67, which is broken by the high-current relay 52and.is established when the coil of the auxiliary relay 67 is energizedthrough thelow current relay tact finger 59, controller segment 58,contact finger 60, contact terminal 73, interlock 68, contact terminal 72, coil of the auxiliary relay 67, contact terminal 53, relay 52 andcontact terminal 54, to the other terminal of the battery B.

Various modifications in the system and improvements in the operationthereof may be efiected without departing from the spirit and scope ofmy invention, and I desire, therefore, that only such limitations shallbe imposed as are indicated in the appended claims.

I claim as my invention:

1. In a control system, the combination with a commutator motor havingarmature and field-magnet windings, of limit switches in the circuit ofsaid field windings and electro-responsive means controlled by saidlimit switches for automatically varying the voltage supplied to thefield windings in direct proportion to the value of the current suppliedthereto.

2. In a control system, the combination with an alternating-currentmotor having armature and field-magnet windings, and anauto-transformer, of limit switches in the circuit of said fieldwindings and electroresponsive means controlled by said limit switchesfor governing the operation of said auto-transformer to automaticallyvary the Thus, the auxil-' iary relay 67 is operated, the interlock 69.isdisengaged from contact terminals 7 3 and 74, the interlock 70 engagescontact terminals and 76 and the interlock 68 is disen-;

the switches 40 and 41- from being simultaneously operated to shortoperate the high-cup rent relay 52, the circuit for the coil oft-thevoltage supplied to the 'field windings in direct proportion to thevalue of the current supplied thereto.

3 3; Ina control system, the combination with a motor having inducingfield-magnet windings, and a source of current therefor, of means forreducing the voltage supplied to the inducing field windings in case thecurrent supplied thereto falls below a predetermined value.

4. In a control system, with analternating-current motor of thecommutator type having inducing field-mag net windings, of switchingmeans for connecting said motor as a doubly-fed motor, andelectro-responsive means for varying thevoltage supplied to the inducingfield windings in accordance with the current supplied-thereto.

' 5. In a control system, the combination with an alternating-currentmotor of the commutator type having exciting and informer connected tothe circuit of said 'inducing field windings, and limit switches in thecircuit of said inducing field windings, of: means controlled by said Ilimit switches for governing the operation of said auto-transformer tovary the voltage supplied to said inducing field windings inaccordance'with the value of the current supplied thereto.

r "6. In a-control system, 'the combination w-ith a'halternating-current motor of the commutator type having exciting andinducing field-magnet windings, and a source of alternating currenttherefor, of electroresponsive means for automatically reducing thevoltage supplied to the inducin field windings in case the currentsupplied thereto falls below a predetermined value and for increasingthe voltage supplied to the inducing fields in case the current risesabove a predetermined value.

7. In a control system, the combination with an alternating-currentmotor of the commutator type having exciting and inducing field-magnetwindings, a source of alternating current, and an auto-transformeradapted to be disposed across a portion of said source of current, ofcurrent relays for controlling the connection of said autotransformer tosaid course for varying the voltage supplied to said inducing field inaccordance with the value of the current supplied thereto.

8. In a control system, the combination with an alternating-currentmotor of the commutator type having field-magnet windings, a source ofalternating current, an auxiliary transformer, switches for connectingthe respective ends of said transformer to different fieldmagnetwindings, one of said switches being initially closed and the other ofsaid switches being initially open,

adapted to de7e'nerg1ze said main transformer auxiliary relay, a low cutrent relay adapt ed to energize auxiliary relay when the motor currentdecreases to a predeterminedlow value, saida-uxiliary relay beinginitially closed" switch and. to. close said initiallyopenswitch, and ahigh-current relay adapted to denergize said auxiliary relay and returnsaid switches. to; When the motor current increases above: apredetermined value.

t9. a control. system, the combination with alternatin torrent: motor ofthe: commutator type having stator windings; a for supplying cm'rent to:said motor, switches: forzconnectingone terminal of said: windings, to.the main trans former, an. azuto-transiormemmeans fioricon trolling theoperation thereofirhilghuand low current relays, disposed I in: thecircuit of said windings, trolled; by said high said relays and togovern the operation of said; former controllingr' means to 'vary the"-voltage of the. current supplied to said Wind+ ingsin accordance with:the current sup:- plied thereto,

10;, In a control system, the combination with a main supply transformerand: asizigle-phase commutator motor having an. in;

their initial position and an. auxiliary: relay conandloW-eurrentirelays, said. switches being adapted ante-trams subscribedname: 213th.

saicli auxiliary transformee said ail-X diary tram omer aetess a o'fisaid mamvtransformer when the motor currentdecreases minedlarge-realize. I I V r In: a eontmlsystem,. the combination witha=meintranszformer vamt-a commutator motor having an armamureucireititand in duping fieldswinding: circuit; each; 015 said. eimuiits"connected, aairosgportions ofi said: main; transfomnenofiane auxiliarytransformer; ele ctzzoe. .siyei meaHs for" automatically'eoimecting'said inducingifieM circuit. across a" portion of saic'lfauxiliary transformer when-1 predetermined operating conditions prevail;and switchingmeans for conneotiia'g said azuxil iaziy transformer aemssaiportion otfisaid' main: transformer.

In. testimony whereof,

day of 13%;,

fr. Monti-sir 1

